Yes we have all had this problem one time or another....the lack of luster to play. It seems like your really improving untill you his one of thse slumps. With my band being on hold now (great time right? It wont be another 2 montsh ebfore we can do gigs) this Bass depression seemed to have come out of nowhere. Im right in the middle of learning therory and now even the circle of fifths seem to bore me....maybe i just need a new bass? Any suggetsions to help me pull my self up out of this one?